Vehicular steering apparatus

ABSTRACT

A vehicular steering apparatus includes a column bracket secured to a steering column; and a fixing bracket secured to a vehicle body. The column bracket includes a top plate and a pair of side plates. The fixing bracket supports the column bracket via a support shaft. A support-shaft through hole formed in each of the side plates of the column bracket includes a slot extended along a longitudinal direction of the steering column. A resilient member is interposed between the top plate of the column bracket and a confronting portion of the support shaft. The resilient member biases the support shaft along a predetermined biasing direction to restrict play of the support shaft in the slot.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a vehicular steering apparatus.

2. Description of Related Art

A vehicular steering apparatus featuring a shock absorbing functionincludes, for example, a type wherein during a collision, a steeringcolumn is adapted to be bodily moved toward a front side of a vehiclebody along a longitudinal direction of the steering column.

On the other hand, a steering apparatus permitting a positionaladjustment of a steering wheel with respect to the longitudinaldirection of the steering column includes a type wherein the whole bodyof the steering column to be adjusted is moved relative to the vehiclebody along the longitudinal direction of the steering column.

The steering column assemblies of the former and latter types normallyhave an arrangement wherein a fixing bracket secured to the vehicle bodyhas a pair of side plates, whereas a column bracket secured to thesteering column is disposed between the pair of side plates of thefixing bracket. The side plates of the column bracket are each formedwith a slot extended along the longitudinal direction of the steeringcolumn. A support shaft inserted through the slots is fixed to thefixing bracket. Thus, the support shaft is allowed to move along theslot when the steering column is moved relative to the vehicle body.

In order to permit the movement of the support shaft along the slot,however, a predetermined clearance need be provided between an outerperiphery of the support shaft and a circumferential edge of the slot.This may result in an unwanted play or poor fit of the steering column.

Therefore, it is a common practice to fit a resin collar for poor-fitelimination on the periphery of the support shaft so that an outerperiphery of the resin collar is fitted in the slot. Unfortunately, aninfluence of varied dimensional tolerances of individual components maylead to a problem that the resin collar is strongly compressed betweenthe circumferential edge of the slot and the outer periphery of thesupport shaft, or conversely that a clearance is produced between theouter periphery of the collar and the circumferential edge of the slot,resulting in the play of the steering column.

The former problem includes an increased resistance to the movement ofthe support shaft along the slot. This may lead to a failure of ensuringa required amount of shock-absorbing stroke because the steering columnbeing moved to absorb an impact energy may be arrested at some midpointof the shock-absorbing stroke. Furthermore, an increased manipulationforce may be required for adjusting the position of the steering wheelwith respect to the longitudinal direction of the steering column.

In view of the foregoing, it is an object of the invention to provide avehicular steering apparatus adapted to prevent the play of the steeringcolumn and to ensure a stable resistance to the relative movementbetween the slot and the support shaft.

SUMMARY OF THE INVENTION

According to a preferred embodiment of the invention for achieving theabove object, there is provided a vehicular steering apparatuscomprising: a column bracket secured to a steering column including atop plate and a pair of side plates; a fixing bracket secured to avehicle body and including a pair of side plates each of which confrontsa face of a corresponding one of the side plate pair of the columnbracket; a support shaft supported by the fixing bracket whilesupporting the column bracket; and a support-shaft through hole formedin each of the side plates of the column bracket and the fixing bracketfor insertion of the support shaft therethrough; wherein thesupport-shaft through holes of the side plates of the column bracketeach include a slot extended along a longitudinal direction of thesteering column for permitting the support shaft to move relativethereto along the longitudinal direction of the steering column; thesteering apparatus further comprising a resilient member interposedbetween the top plate of the column bracket and a confronting portion ofthe support shaft and serving to bias the support shaft in apredetermined biasing direction to restrict play of the support shaft inthe slot.

According to the embodiment, the support shaft is biased by a resilientrepulsive force of the resilient member whereby the play of the steeringcolumn is obviated. As a result, the occurrence of noises and the likecan be prevented. In addition, the resilient member is disposed out ofthe slots so that the resilient member may be disposed at place wherethere is enough room therefor. Accordingly, it is not so difficult toaccomplish a required amount of deformation of the resilient member forobviating the play of the steering column. This results in a stableresistance to the relative movement between the slot and the supportshaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view showing a vehicular steering apparatusaccording to one embodiment of the invention;

FIG. 2 is a sectional view taken on the line II-II in FIG. 1 for showinga part of a support structure of the steering apparatus;

FIG. 3 is a sectional view taken on the line III-III in FIG. 2 forshowing a part of the support structure of the steering apparatus;

FIG. 4 is a sectional view showing a principal part of a vehicularsteering apparatus according to another embodiment of the invention andparticularly illustrating an exemplary modification of a resilientmember;

FIG. 5 is a sectional view showing a principal part of a vehicularsteering apparatus according to still another embodiment of theinvention;

FIG. 6 is a perspective view showing a resilient member of the steeringapparatus of FIG. 5;

FIG. 7 is a sectional view showing a principal part of a vehicularsteering apparatus according to still another embodiment of theinvention;

FIG. 8 is a sectional view showing a principal part of a vehicularsteering apparatus according to still another embodiment of theinvention;

FIG. 9 is a sectional view showing a principal part of a vehicularsteering apparatus according to still another embodiment of theinvention;

FIG. 10 is a perspective view showing a principal part of a vehicularsteering apparatus according to still another embodiment of theinvention;

FIG. 11 is a sectional view showing a principal part of a vehicularsteering apparatus according to still another embodiment of theinvention; and

FIG. 12 is a sectional view showing a principal part of a vehicularsteering apparatus according to still another embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, vehicular steering column assemblies according to preferredembodiments of the invention will be described with reference to theaccompanying drawings.

Referring to FIG. 1, a steering apparatus 1 includes a steering shaft 3for transmitting a motion of a steering wheel 2 for steering dirigiblewheels (not shown); and a steering column 4 rotatably supporting thesteering shaft 3 extended therethrough. The steering wheel 2 isconnected with a first end 3 a of the steering shaft 3. A second end 3 bof the steering shaft 3 is connected with a steering mechanism includinga pinion, a rack shaft and the like, via an intermediate shaft notshown.

The steering mechanism may employ any other known mechanism. When thesteering wheel 2 is turned, the rotation thereof is transmitted to thesteering mechanism via the steering shaft 3, a universal joint, anintermediate shaft and the like so that the dirigible wheels can besteered.

The steering apparatus 1 is assembled to a vehicle body 7 (a partthereof is indicated by a dot-dash line) in a manner, for example, thatthe steering column 4 is inclined along a longitudinal direction Sthereof with respect to an anteroposterior direction of the vehicle bodywhile positioning the steering wheel 2 at an elevated side. However, thefigure depicts the longitudinal direction S along a horizontal line forsimplicity.

The steering column 4 has a cylindrical column jacket 5 for rotatablysupporting the steering shaft 3. First and second ends 5 a, 5 b of thecolumn jacket 5 correspond to the first and second ends 3 a, 3 b of thesteering shaft 3, respectively.

The steering column 4 is provided with a lower column bracket 8 and anupper column bracket 9 for mounting the column jacket 5 to the vehiclebody 7. The lower column bracket 8 is secured to the second end 5 b ofthe column jacket 5, whereas the upper column bracket 9 is secured toplace near the first end 5 a of the column jacket 5.

The column jacket 5 houses a most part of the steering shaft 3 androtatably carries the steering shaft by means of a plurality of, say twobearings (not shown) as axially positioning the steering shaft. It isnoted that the column jacket 5 may consist of a plurality of members. Inaddition, at least either one of the lower column bracket 8 and theupper column bracket 9 may be formed integrally with the column jacket 5to constitute a single member.

The steering apparatus 1 further includes two support structures 11, 12for supportably fixing the steering column 4 to the vehicle body 7.

As shown in FIGS. 1 and 2, the support structure 11 includes the lowercolumn bracket 8 secured to the steering column 4 and defining a grooveshape including a top plate 13 and a pair of side plates 14; a lowerfixing bracket 15 having a pair of side plates 16 sandwiching the lowercolumn bracket 8 therebetween, and secured to the vehicle body 7; and asupport shaft 18 extending through these side plates 14, 16.

The lower fixing bracket 15 further includes a connecting plate 17interconnecting opposite ends of the side plate pair 16. The lowerfixing bracket 15 is secured to the vehicle body 7 via the connectingplate 17 by way of bolts (not shown). The pair of side plates 16 of thelower fixing bracket 15 each confront an outside face 14 a of acorresponding one of the side plates 14 of the lower column bracket 8.The pair of side plates 16 of the lower fixing bracket 15 are eachformed with a circular through hole 19, whereas the pair of side plates14 of the lower column bracket 8 are each formed with a slot 20 forinsertion of the support shaft therethrough. The slot 20 extends alongthe longitudinal direction S of the steering column 4.

The support shaft 18 includes a hollow outer shaft 25, and an innershaft 22 coaxially inserted through the outer shaft 25. The outer shaft25 is interposed between the pair of side plates 16 of the lower fixingbracket 15 and inserted through the slots 20, as the support-shaftinsertion hole, in the pair of side plates 14 of the lower columnbracket 8. The outer shaft 25 presents a pair of opposite ends thereofto corresponding inside faces 16 a of the side plates 16.

The inner shaft 22 is a threaded stem having a head 23 at one endthereof and a threaded portion at the other end thereof. The inner shaft22 extends through the support-shaft through holes 19 in the pair ofside plates 16 of the lower fixing bracket 15 and the hollow outer shaft25.

The pair of side plates 16 of the lower fixing bracket 15 and the hollowouter shaft 25 are integrally held onto a portion between a nut 26fitted on the threaded portion at the other end of the inner shaft 22and the head 23 thereof. Specifically, the outer shaft is restrictedfrom moving axially of the support shaft 18 as held between the oppositeside plates 16 of the lower fixing bracket 15.

Although a structure omitting the outer shaft 25 may be contemplated,the embodiment is described by way of the example where the outer shaft25 is provided.

The lower fixing bracket 15 supports the lower column bracket 8 by wayof the support shaft 18 including the inner shaft 22 and the outer shaft25. The support shaft 18 pivotally supports the steering column 4 viathe lower column bracket 8. That is, the support shaft 18 functions as atilt axis or a pivot shaft for tilt adjustment of the steering column 4.

The lower fixing bracket 15 supports the support shaft 18 in a manner topermit the support shaft 18 to move relative to the steering column 4along the longitudinal direction S thereof.

As shown in FIG. 1, the support structure 12 includes the upper columnbracket 9 secured to the steering column 4 and including a pair of sideplates 30; an upper fixing bracket 33 having a pair of side plates 34sandwiching the upper column bracket 9 therebetween and secured to thevehicle body 7; and a support shaft 37 extending through the side plates30, 34 of the brackets 9, 33.

The upper fixing bracket 33 is supported by the vehicle body 7 via acoupling member 40. The pair of side plates 34 of the upper fixingbracket 33 are each formed with a vertically elongated support-shaftthrough hole 35. The support-shaft through hole 35 extends along adirection V orthogonal to the longitudinal direction of the steeringcolumn 4.

The pair of side plates 30 of the upper column bracket 9 are each formedwith a horizontally elongated support-shaft through hole 31. Thesupport-shaft through hole 31 extends along a direction parallel to thelongitudinal direction S of the steering column 4.

The support shaft 37 extends through the vertically elongated throughholes 35 and the horizontally elongated through holes 31 so as tointerconnect the brackets 9, 33. Thus, the upper column bracket 9 andthe upper fixing bracket 33 are allowed to move relative to each otheralong the directions of the support-shaft through holes 35, 31.

The support shaft 37 is provided with a lock mechanism 41 for releasablyholding the brackets 9, 33 in a tilt-lock state to inhibit the relativemovements of the brackets 9, 33.

The lock mechanism 41 includes an operation lever 42 turned about anaxis of the support shaft 37 to switch the brackets between thetilt-lock state and the released state; and a cam mechanism (not shown)which is operatively associated with the turning of the operation lever42 so as to press the corresponding side plates 30, 34 of the brackets9, 33 against each other for establishing the tilt-lock state. The lockmechanism 41 may employ any known mechanism for pressing the side plates30, 34 against each other.

When the operation lever 42 is turned in a predetermined direction, thecam mechanism establishes the tilt-lock state by pressing the sideplates 30, 34 of the brackets 9, 33 against each other, so that thesteering column 4 is retained with a given retention force. Thetilt-lock state may be canceled by turning the operation lever 42 in theopposite direction to the predetermined direction.

The released state permits the implementation of the tilt adjustmentfunction to adjust the height of the steering wheel 2 by pivotallymoving the steering column 4 about the support shaft 18 as the tiltaxis; and a function to adjust the longitudinal position of the steeringwheel 2 by slidably moving the steering column 4 along the lingitudinaldirection of the steering column 4 being guided by the support shaft 37and the support shaft 18.

The steering apparatus 1 of the invention also has an shock absorbingcapability to absorb an impact energy of a driver (operator) strikingthe steering wheel 2 during a collision. Specifically, the couplingmember 40 of the support structure 12 has, for example, a so-calledcapsule structure. The coupling member 40 normally retains the upperfixing bracket 33 onto the vehicle body 7 with a predetermined retentionforce such as to constrain the bracket 33 in place. During a collision,however, the coupling member 40 permits the upper fixing bracket 33 tomove relative to the vehicle body 7 toward the front side thereof. Thus,the steering column 4 is moved toward the front side of the vehicle bodyso that the impact energy of the collision is absorbed. Instead of thecapsule structure, the coupling member 40 may employ any other knownstructure that connects the steering column with the vehicle body 7 in amanner to permit the relative movement of the steering column during acollision.

When the steering column 4 is moved relative to the vehicle body 7 alongthe longitudinal direction S, the support shafts 18 and 37 are guided bythe corresponding slots 20, 31. In the normal adjustment of thelongitudinal position of the steering column 4, both the support shafts18, 37 are allowed to move as guided within positional adjustmentregions of the corresponding slots 20, 31. During the absorption of animpact energy, both the support shafts 18, 37 are introduced intorespective impact absorption regions closer to the steering wheel 2 thanthe positional adjustment regions, so as to be moved in the respectiveimpact absorption regions.

According to the embodiment, an annular member 45 as a resilient memberis fitted on, for example, a periphery of an axially intermediateportion 44 of the outer shaft 25 of the support shaft 18, as shown inFIGS. 2 and 3. The annular member 45 is interposed between the top plate13 of the lower column bracket 8 and the outer shaft 25 as a confrontingportion of the support shaft 18, and elastically biases the supportshaft 18 in a predetermined biasing direction F to restrict a radialplay of the support shaft 18 in the slot 20 or of the outer shaft 25.

In the embodiment, the radial play of the support shaft 18 means playalong the direction V substantially orthogonal to the longitudinaldirection S of the steering column 4. The predetermined biasingdirection F to restrict such a play may be a direction to intersect aplane including the longitudinal direction S of the steering column 4and an axial direction of the support shaft 18. What is important isthat the annular member 45 as the resilient member biases the supportshaft 18 along such a direction.

The annular member 45 may be formed in a cylindrical shape using a knownelastic material such as rubber, resin or the like. The outer shaft 25of the support shaft 18 is inserted through a hole of the annular member45, an outer periphery 46 of which is in contact with an inside surfaceof the top plate 13.

The annular member 45 is radially compressed at its portion clampedbetween the axially intermediate portion 44 of the outer shaft 25 andthe top plate 13, the compressed portion producing an elastic restoringforce acting to return the annular member to a non-compressed state.Because of the above elastic restoring force, the annular member 45biases the outer shaft 25 of the support shaft 18 away from the topplate 13. Thus, the outer shaft 25 is pressed against a circumferentialedge of the slot 20 while both the brackets 8, 15 are biased in oppositedirections.

The annular member 45 is relatively rotatably fitted around the outershaft 25 and carried on the support shaft 18. The support shaft 18 andthe annular member 45 are unitarily movable relative to the steeringcolumn 4.

It may be contemplated to design the annular member 45 to be held ontothe outer shaft 25 as restricted from rotating relative to the outershaft. It is also possible to use an O ring as the annular member 45.This is a convenient way to obtain an working effect of the annularmember 45.

The resilient member is not limited to the annular member 45. Forinstance, the annular member 45 may be replaced by any one of thefollowing members illustrated in FIGS. 4 to 11. The annular member 45 orany one of the following members may be used alone. Otherwise, pluralmembers of different types or of one type may be used. What is needed isto employ at least one resilient member. The following description onthe modifications of the invention focuses on differences from the aboveembodiment while like components to those already described arerepresented by the same reference numerals, respectively.

According to FIG. 4, a spiral spring 80 is provided as the resilientmember. The spiral spring 80 is constructed from an elongate sheet metalof a known resilient material such as a spring steel, which issubstantially worked into a spiral shape. The spiral spring 80 has thespiral shape as viewed along the axis of the support shaft 18 and apredetermined width with respect to the axial direction of the supportshaft 18. The spiral spring 80 internally defines a cavity 81surrounding the outer shaft 25 of the support shaft 18. The supportshaft 18 extends through the cavity 81, thereby retaining thereon thespiral spring 80.

The spiral spring 80 has a first portion 82 defined near a center of thespiral shape, and a second portion 83 defined by an outer circumferenceportion of the spiral shape. The first portion 82 is in contact with theouter shaft 25 of the support shaft 18, whereas the second portion 83 isin contact with the top plate 13.

The spiral spring 80 is retained by the support shaft 18 in a mannerthat the spiral spring is pressurized to bring its first and secondportions 82, 83 into close face-to-face relation. Hence, the spiralspring 80 produces a resilient restoring force acting to move the firstand second portions 82, 83 thereof away from each other, thereby biasingthe support shaft 18 along a predetermined biasing direction F to movethe support shaft 18 away from the top plate 13.

The spiral spring 80 has an outward configuration substantially of anellipse and is so positioned as to align a greater diameter of theelliptical shape with the longitudinal direction S of the steeringcolumn 4. This provides for an autonomous control of the position of thespiral spring 80 such that the first and second portions 82, 83 thereofare aligned on a smaller diameter of the elliptical shape. As a result,the spiral spring 80 is prevented from rotating during the relativemovement between the support shaft 18 and the slot 20 and hence, thesecond portions 83 is assuredly maintained in sliding contact with thetop plate 13.

Alternatively, a resilient member 85 of a leaf spring may be used, asshown in FIGS. 5 and 6. The resilient member 85 includes a main body 86retained by the support shaft 18; and a pair of arm portions 87 of leafspring extended from the main body 86 to resiliently contact the topplate 13. The arm portions 87 extend from the main body 86 in oppositedirections and along the longitudinal direction S of the steering column4. Each of the arm portions 87 defines a curved shape protruded towardthe top plate 13.

The resilient member 85 is formed from a known resilient material suchas a spring steel. The resilient member 85 is substantially shaped like‘Y’ as viewed along the axis of the support shaft 18.

The arm portions 86 are each cantilevered by the main body 86 and eachabut against the top plate 13 at a portion near a free end thereof. Theouter shaft 25 of the support shaft 18 is fitted into a through hole 91of the main body 86, whereby the resilient member 85 with its armportions 87 subject to bending deformation is retained by the supportshaft 18 in a manner to be movable unitarily with the support shaft 18.The arm portions 87 each exhibit a resilient repulsive force to bias thesupport shaft 18 via the main body 86 along a predetermined biasingdirection F to move the support shaft 18 away from the top plate 13.

The arm portions 87 receive reaction forces from the top plate 13, whichproduce torques oppositely directed about the support shaft 18 so thatthe resilient member 85 is prevented from rotating about the supportshaft 18 during the relative movement between the support shaft 18 andthe slot 20.

The main body 86 defines a groove shape including a pair of side plates89 each including the through hole 91, and a top plate 90interconnecting upper ends of the side plates 89. There may be a case,for example, where the main body 86 and the pair of arm portions 87 areformed from a metal sheet as one piece. In this case, the resilientmember 85 is formed of a metal-sheet work piece having a substantiallydeveloped shape of a cross.

FIG. 7 illustrates a torsion helical spring 50 as the resilient member.The torsion helical spring 50 is formed from a known resilient materialsuch as a spring steel. The torsion helical spring 50 includes a helicalportion 51 retained by the support shaft 18 as surrounding the same; anda pair of extension portions 52 each extended tangentially of thehelical portion 51. The pair of extension portions 52 are extendedgenerally in opposite ways to substantially define a V-shape, and alongthe longitudinal direction S of the steering column 4.

The extension portions 52 are cantilevered by the helical portion 51 andeach abut against the top plate 13 at a free end thereof. The torsionhelical spring 50 is so deformed as to increase the angle of the V-shapedefined by the pair of extension portions 52. A resilient restoringforce against the deformation is produced so that the torsion helicalspring 50 biases the support shaft 18 along a predetermined biasingforce F to move the support shaft 18 away from the top plate 13.

The extension portions 52 receive reaction forces from the top plate 13,which produce torques oppositely directed about the support shaft 18 sothat the torsion helical spring 50 is prevented from rotating about thesupport shaft 18 during the relative movement between the support shaft18 and the slot 20.

As shown in FIG. 8, an extension spring 56 may be used as the resilientmember. The extension spring 56 may be formed from a known resilientmaterial such as a spring steel. The extension spring 56 includes anexpandable helical main body 57. The extension spring 56 is formed witha pair of engaging portions 58 such as of hooks at opposite endsthereof.

The pair of engaging portions 58 of the extension spring 56 areindividually hooked over the periphery of the outer shaft 25 of thesupport shaft 18 and through an engagement portion 59 such as of anengagement hole formed in the top plate 13. The extension spring 56 isstretched between the top plate 13 and the support shaft 18.

The engagement portion 59 formed in the top plate 13 is spaced away fromthe support shaft 18 with respect to the longitudinal direction S of thesteering column 4. Specifically, a distance between the steering wheel 2and the engagement portion 59 of the top plate 13 is greater than adistance between the steering wheel 2 and the support shaft 18.

A resilient restoring force of the extension spring 56 biases thesupport shaft 18 along a predetermined biasing direction F to move thesupport shaft 18 toward the engagement portion 59 of the top plate 13.The support shaft 18 is also biased along the longitudinal direction Sof the steering column 4 by a component force of the biasing forceacting along the predetermined biasing direction F.

According to the example shown in FIG. 8, the engagement hole isemployed as the engagement portion 59 of the top plate 13.Alternatively, the engagement portion 59 may be, for example, anengagement projection over which the corresponding engaging portion 58of the extension spring 56 can be hooked.

In addition, the distance between the steering wheel 2 and theengagement portion 59 of the top plate 13 may be smaller than thedistance between the steering wheel 2 and the support shaft 18, orotherwise, these distances may be substantially equal to each other sothat the engagement portion 59 confronts the support shaft 18.

Furthermore, as a resilient member for restricting the play of thesupport shaft 18, there may be used cantilever resilient tongues 60, 65formed integrally with the top plate 13 of the lower column bracket 8 asshown in FIG. 9 or 10, or a resilient projection 70 protruded from thetop plate 13.

The resilient projection 60 shown in FIG. 9 is fixed to the top plate 13at one end 61 thereof, defining a free end at the other end thereof.Thus, the resilient projection is cantilvered by the top plate. Theresilient projection 60 extends from the one end 61 thereof to the otherend thereof along the longitudinal direction S of the steering column 4so as to bias the axially intermediate portion 44 of the outer shaft 25at its portion extending in parallel with the slot 20.

Similarly to the resilient projection 60 of FIG. 9, the resilientprojection 65 shown in FIG. 10 is cantilevered. The resilient projection65 extends from one end 66 thereof to the other end 67 thereof inparallel with the axial direction of the support shaft 18 and biases theaxially intermediate portion 44 of the outer shaft 25 at the other end67 thereof.

The resilient projection 70 shown in FIG. 11 is formed by protruding apart of the top plate 13 toward the support shaft 18, and has a convexdistal end 71 biasing the axially intermediate portion 44 of the outershaft 25 of the support shaft 18.

According to the foregoing embodiments, the resilient members such asthe annular member 45, spiral spring 80, resilient member 85, torsionhelical spring 50, extension spring 56, resilient tongues 60, 65 andresilient projection 70 each have at least a part thereof resilientlydeformed for biasing the support shaft 18, thereby preventing theunwanted play or rattle of the steering column 4. This will lead to thesuppression of noises.

Furthermore, the resilient members 45, 80, 85, 50, 56 are each disposedat place where there is enough room therefor. Accordingly, it is not sodifficult to accomplish a required amount of deformation of theresilient member for obviating the poor fit of the support shaft 18.This results in a stable resistance to the relative movement between theslot 20 and the support shaft 18 when the steering column 4 is movedalong the longitudinal direction S thereof for positional adjustment ofthe steering wheel 2 or for absorption of an impact energy.

This also leads to the reduced variations in the resistance among theindividual steering column assemblies 1 and thence, to the reducedvariations in the amount of absorbed impact energy. Furthermore, it isensured that a required shock-absorbing stroke is positively attained.In addition, the individual steering column assemblies 1 are less variedin the manipulation force to be applied for adjusting the position ofthe steering wheel 2 thereof.

Any of the above members 45, 80, 85, 50, 56 may be utilized to eliminatethe poor fit and hence, the poor-fit eliminating collar of resinmentioned in the section of the related art, for example, may be omittedas in the foregoing embodiments. The omitted collar means the reductionof the number of components and the costs.

Where the annular member 45 is used as the poor-fit eliminatingresilient member, for example, the annular member 45 may have a muchgreater size than the conventional resin collar singly inserted in theslot. Therefore, the annular member is decreased in the ratio of arequired amount of deformation for poor-fit elimination relative to thesize thereof.

As a result, it is ensured that the required amount of deformation forpoor-fit elimination is achieved in a stable manner less affected bydimensional errors of the components such as the annular member 45.Hence, the resistance to the relative movement between the slot 20 andthe support shaft 18 is not varied.

In contrast, the conventional example employs only the resin collarfitted in the slot as fitted on the support shaft for eliminating thepoor fit of the support shaft in the slot. Since the resin collar isnormally small in size, the collar has a great ratio of the requiredamount of deformation for poor-fit elimination relative to the sizethereof. Consequently, the conventional example is significantlyaffected by the dimensional errors of the components, suffering greatvariations in the required amount of deformation and the resistance tothe relative movement.

It is noted here that the required amount of deformation for poor-fitelimination means an amount of deformation to enable the poor-fiteliminating member to eliminate a clearance between the slot 20 and thesupport shaft 18 while accommodating clearance amount variationsresulting from the dimensional errors. The same holds for the otherresilient members 80, 85, 50, 65 besides the annular member 45.

It goes without saying that the working effect of the invention is alsoachieved in a case where each of the foregoing embodiments employs thecorresponding one of the members 45, 80, 85, 50, 65 as the resilientmember in combination with the conventional resin collar (not shown)fitted in the slot 20 as fitted on the periphery of the support shaft18. That is, since the poor fit is obviated by the resilient member,there is no problem if a clearance exists between a periphery of theresin collar and the circumferential edge of the slot 20. Therefore,dimensional tolerance for the resin collar may be defined out of a rangewhich results in an increased resistance to the relative movementbetween the slot and the support shaft. As a result, the variations ofthe resistance to the relative movement are decreased, so that theproblem is solved.

The annular member 45, spiral spring 80, resilient member 85 and torsionhelical spring 50 are preferred for preventing the poor fit of thesupport shaft 18 because these members can keep biasing the supportshaft 18 as slidably contacting the top plate 13 when the steeringcolumn 4 is moved. These members, which are in friction contact with thetop plate 13, are also able to absorb the shock during a collision.

The annular member 45 can roll or slide on the top plate 13 when thesteering column 4 is moved. Accordingly, the annular member is preferredfor stabilizing and reducing the resistance to the relative movementbetween the slot 20 and the support shaft 18. For instance, the annularmember is preferably used for ensuring the required amount ofshock-absorbing stroke during the shock absorption. Furthermore, theannular member permits a small manipulation force to move the steeringcolumn 4 along the longitudinal direction S thereof for positionaladjustment of the steering wheel 2.

Where the extension spring 56 is employed, the poor fit of the supportshaft 18 can be readily obviated by the extension spring 56.Particularly, the extension spring is capable of adjusting the positionof the steering wheel 2 with respect to the longitudinal direction S ofthe steering column 4. In addition, where the engagement portion 59 ofthe top plate 13 is located farther away from the steering wheel 2 thanthe support shaft 18, the extension spring 56 receives a weight of thesteering column 4 in place of an operator, thus reducing themanipulation force for manually moving the steering column 4 forpositional adjustment.

In a case where the steering apparatus 1 does not have the function topermit the positional adjustment of the steering wheel 2 with respect tothe longitudinal direction S of the steering column 4 or where theassembly 1 does not have the above function nor the tilt adjustmentfunction, the support shaft 18 is designed to be moved in the slot 20only when the shock is absorbed.

In a case where the steering apparatus 1 does not have the aforesaidshock absorbing function but has any other known shock absorbingmechanism at some other place therein, or where this assembly furtheromits the tilt adjustment function, the support shaft 18 is designed tobe moved in the slot 20 only when the steering wheel 2 is adjusted forits position with respect to the longitudinal direction S of thesteering column 4.

In addition, the outer shaft 25 of the support shaft 18 may be dispensedwith so that the support shaft includes only the inner shaft 22.

It may be contemplated that any one of the above resilient members isprovided at the support structure 12. Specifically, where the uppercolumn bracket 9 of the support structure 12 defines a groove shapeincluding a top plate 32 and the pair of side plates 30, as shown inFIG. 12, the above resilient member, such as the annular member 45(schematically depicted in the figure), is interposed between an axiallyintermediate portion 38 of the support shaft 37 sandwiched between thepair of side plates 30 of the upper column bracket 9, and the top plate32 of the upper column bracket 9, so that the resilient member may biasthe support shaft 37 in a predetermined biasing direction F to restrictthe poor fit of the support shaft 37 in the slots 31 as thesupport-shaft insertion holes formed in the side plates 30.

The pair of side plates 34 of the upper fixing bracket 33 each confrontan outside face 30 a of a corresponding one of the side plates 30 of theupper column bracket 9.

The support shaft 37 may have the same two-piece structure as theaforementioned support shaft 18 but may consist of a single solid bolt.

Where any of the above members 45, 80, 85, 50, 56 as the resilientmember is provided at the support structure 12, the resilient member ofthe support structure 11 may be dispensed with.

While the invention has been specifically described by way of thespecific examples thereof, modifications, changes or equivalents theretowill occur to those skilled in the art fully understanding the abovedescription. The scope of the invention is therefore to be determined bythe following claims and equivalents thereto.

This application is based on JP-A-2002-1374 filed with the Japan Patentoffice on May 13, 20002, the disclosure of which is incorporated hereinby reference.

1. A vehicular steering apparatus comprising: a column bracket securedto a steering column including a top plate and a pair of side plates; afixing bracket secured to a vehicle body and including a pair of sideplates each of which confronts a face of a corresponding one of the sideplate pair of the column bracket; a support shaft supported by thefixing bracket while supporting the column bracket; a support-shaftthrough hole formed in each of the side plates of the column bracket andthe fixing bracket for insertion of the support shaft therethrough; thesupport-shaft through holes of the side plates of the column bracketeach including a slot extended along a longitudinal direction of thesteering column for permitting the support shaft to move relativethereto along the longitudinal direction of the steering column; and aresilient member interposed between the top plate of the column bracketand a confronting portion of the support shaft and serving to bias thesupport shaft in a predetermined biasing direction to restrict play ofthe support shaft in the slot; wherein the resilient member includes anextension spring, a pair of ends of which are individually engaged withthe support shaft and the top plate. 2-12. (canceled)
 13. A vehicularsteering apparatus according to claim 1, wherein the extension spring isable to receive a part of load of the steering column via the supportshaft. 14-15. (canceled)
 16. A vehicular steering apparatus according toclaim 1, wherein the support shaft includes a hollow outer shaft and aninner shaft inserted through the outer shaft, the resilient memberengages the outer shaft, and the outer shaft is held between the pair ofside plates of the fixing bracket. 17-19. (canceled)